Computation of unsteady flow fields and trajectories of moving bodies

• Main Author: Aditya Mahesh Khatri
• Other Authors: Damodaran Murali
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Mechanical engineering::Fluid mechanics
• Online Access: http://hdl.handle.net/10356/17154
• Institution: Nanyang Technological University

Fluid body interaction is a phenomenon that is simple to observe, but very complicated to understand. It affects many aspects in our daily lives; waves pushing against a buoy or flags fluttering in the wind. This study seeks to understand fluid-body interaction by looking at how flow structures are created over a body placed in a uniform flow, obtain useful flow characteristics and then provide a simple model of how fluid-body interaction takes place. Firstly, steady and unsteady computations of uniform flow over a rotating circular cylinder at various Reynolds numbers and rotation rates are carried out. This is followed by an unsteady computation of the flow structures over a single non-rotating cylinder flanked by two smaller rotating cylinders placed in a uniform flow. Finally, a simple constrained two-dimensional computation of a rigid body in free-fall is carried out to observe the trajectory and flow characteristics of the body. It is seen that the flow structures obtained from both the rotating cylinder cases are similar to those obtained computationally, as well as experimentally. It is also seen that in the case of the falling body problem, the moment of inertia of the body as well as the flow structures created as the body undergoes free-fall play an important part in the flow characteristics and behavior. Fluid body interaction has potential applications in flapping and adaptive wing studies, and therefore, it is suggested that further studies investigating the effects of existing flow structures on simple body flow characteristics, as well as the effects of interaction between uniform and rotating flow structures be carried out.